ui/app: introduce DrawEvent.Insets and add Android implementation

Signed-off-by: Elias Naur <mail@eliasnaur.com>

ui/app/GioActivity.java

@@ -6,6 +6,7 @@ import android.app.Activity;
 import android.content.res.Configuration;
 import android.os.Build;
 import android.os.Bundle;
+import android.view.View;
 import android.view.Window;
 import android.view.WindowManager;
 
@@ -15,12 +16,13 @@ public class GioActivity extends Activity {
 	@Override public void onCreate(Bundle state) {
 		super.onCreate(state);
 
-		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
 		Window w = getWindow();
-			w.setFlags(WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS, WindowManager.LayoutParams.FLAG_LAYOUT_NO_LIMITS);
+		if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
+			w.addFlags(WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS);
 		}
 
 		this.view = new GioView(this);
+		this.view.setLayoutParams(new WindowManager.LayoutParams(WindowManager.LayoutParams.MATCH_PARENT, WindowManager.LayoutParams.MATCH_PARENT));
 		setContentView(view);
 	}
 

ui/app/GioView.java

@@ -3,6 +3,7 @@
 package org.gioui;
 
 import android.content.Context;
+import android.graphics.Rect;
 import android.os.Build;
 import android.os.Handler;
 import android.util.AttributeSet;
@@ -12,6 +13,7 @@ import android.view.KeyCharacterMap;
 import android.view.KeyEvent;
 import android.view.MotionEvent;
 import android.view.View;
+import android.view.WindowInsets;
 import android.view.Surface;
 import android.view.SurfaceView;
 import android.view.SurfaceHolder;
@@ -157,6 +159,11 @@ public class GioView extends SurfaceView implements Choreographer.FrameCallback
 		});
 	}
 
+	@Override protected boolean fitSystemWindows(Rect insets) {
+		onWindowInsets(nhandle, insets.top, insets.right, insets.bottom, insets.left);
+		return true;
+	}
+
 	void postFrameCallback() {
 		Choreographer.getInstance().removeFrameCallback(this);
 		Choreographer.getInstance().postFrameCallback(this);
@@ -207,6 +214,7 @@ public class GioView extends SurfaceView implements Choreographer.FrameCallback
 	static private native void onSurfaceDestroyed(long handle);
 	static private native void onSurfaceChanged(long handle, Surface surface);
 	static private native void onConfigurationChanged(long handle);
+	static private native void onWindowInsets(long handle, int top, int right, int bottom, int left);
 	static private native void onLowMemory();
 	static private native void onTouchEvent(long handle, int action, int pointerID, int tool, float x, float y, long time);
 	static private native void onKeyEvent(long handle, int code, int character, long time);

ui/app/app.go

@@ -17,6 +17,10 @@ type Event interface {
 type DrawEvent struct {
 	Config ui.Config
 	Size   image.Point
+	// Insets is the window space taken up by
+	// system decoration such as translucent
+	// system bars and software keyboards.
+	Insets image.Rectangle
 	// Whether this draw is system generated
 	// and needs a complete frame before
 	// proceeding.

ui/app/datadir_android.go

@@ -15,4 +15,3 @@ func setDataDir(cdir *C.char) {
 		return dir, nil
 	}
 }
-

ui/app/os_android.c

@@ -53,6 +53,11 @@ JNIEXPORT jint JNI_OnLoad(JavaVM *vm, void *reserved) {
 			.signature = "(J)V",
 			.fnPtr = onConfigurationChanged
 		},
+		{
+			.name = "onWindowInsets",
+			.signature = "(JIIII)V",
+			.fnPtr = onWindowInsets
+		},
 		{
 			.name = "onLowMemory",
 			.signature = "()V",

ui/app/os_android.go

@@ -37,6 +37,7 @@ type window struct {
 
 	dpi       int
 	fontScale float32
+	insets    image.Rectangle
 
 	stage   Stage
 	started bool
@@ -197,6 +198,18 @@ func onFocusChange(env *C.JNIEnv, class C.jclass, view C.jlong, focus C.jboolean
 	w.event(key.FocusEvent{Focus: focus == C.JNI_TRUE})
 }
 
+//export onWindowInsets
+func onWindowInsets(env *C.JNIEnv, class C.jclass, view C.jlong, top, right, bottom, left C.jint) {
+	w := views[view]
+	w.insets = image.Rectangle{
+		Min: image.Point{X: int(left), Y: int(top)},
+		Max: image.Point{X: int(right), Y: int(bottom)},
+	}
+	if w.stage >= StageRunning {
+		w.draw(true)
+	}
+}
+
 func (w *window) setVisible() {
 	win := w.aNativeWindow()
 	width, height := C.ANativeWindow_getWidth(win), C.ANativeWindow_getHeight(win)
@@ -275,6 +288,7 @@ func (w *window) draw(sync bool) {
 			X: int(width),
 			Y: int(height),
 		},
+		Insets: w.insets,
 		Config: ui.Config{
 			PxPerDp: ppdp,
 			PxPerSp: w.fontScale * ppdp,